// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//
//-----------------------------------------------------------------------------

#define _POSIX_C_SOURCE 200112L  // Required to get gethostname()

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/ioctl.h>

#include "i_system.h"
#include "d_event.h"
#include "d_net.h"
#include "m_argv.h"

#include "doomstat.h"

#include "i_net.h"

// For some odd reason...
#ifndef ntohl
#define ntohl(x) \
        ((unsigned long int)((((unsigned long int)(x) & 0x000000ffU) << 24) | \
                             (((unsigned long int)(x) & 0x0000ff00U) <<  8) | \
                             (((unsigned long int)(x) & 0x00ff0000U) >>  8) | \
                             (((unsigned long int)(x) & 0xff000000U) >> 24)))
#endif

#ifndef ntohs
#define ntohs(x) \
        ((unsigned short int)((((unsigned short int)(x) & 0x00ff) << 8) | \
                              (((unsigned short int)(x) & 0xff00) >> 8)))
#endif

#ifndef htonl
#define htonl(x) ntohl(x)
#endif
#ifndef htons
#define htons(x) ntohs(x)
#endif

void    NetSend (void);
boolean NetListen (void);

//
// NETWORKING
//

int     DOOMPORT =      5029;

int                     sendsocket;
int                     insocket;

struct  sockaddr_in     sendaddress[MAXNETNODES];

void    (*netget) (void);
void    (*netsend) (void);

//
// UDPsocket
//
int UDPsocket (void)
{
    int s;

    // allocate a socket
    s = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (s<0)
        I_Error ("can't create socket: %s",strerror(errno));

    return s;
}

//
// BindToLocalPort
//
void
BindToLocalPort
( int   s,
  int   port )
{
    int                 v;
    struct sockaddr_in  address;

    memset (&address, 0, sizeof(address));
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = port;

    v = bind (s, (void *)&address, sizeof(address));
    if (v == -1)
        I_Error ("BindToPort: bind: %s", strerror(errno));
}

//
// PacketSend
//
void PacketSend (void)
{
    int         c;
    doomdata_t  sw;

    // byte swap
    sw.checksum = htonl(netbuffer->checksum);
    sw.player = netbuffer->player;
    sw.retransmitfrom = netbuffer->retransmitfrom;
    sw.starttic = netbuffer->starttic;
    sw.numtics = netbuffer->numtics;
    for (c=0 ; c< netbuffer->numtics ; c++)
    {
        sw.cmds[c].forwardmove = netbuffer->cmds[c].forwardmove;
        sw.cmds[c].sidemove = netbuffer->cmds[c].sidemove;
        sw.cmds[c].angleturn = htons(netbuffer->cmds[c].angleturn);
        sw.cmds[c].consistancy = htons(netbuffer->cmds[c].consistancy);
        sw.cmds[c].chatchar = netbuffer->cmds[c].chatchar;
        sw.cmds[c].buttons = netbuffer->cmds[c].buttons;
    }

    //printf ("sending %i\n",gametic);
    c = sendto (sendsocket , &sw, doomcom->datalength
                ,0,(void *)&sendaddress[doomcom->remotenode]
                ,sizeof(sendaddress[doomcom->remotenode]));

    //  if (c == -1)
    //          I_Error ("SendPacket error: %s",strerror(errno));
}

//
// PacketGet
//
void PacketGet (void)
{
    int                 i;
    int                 c;
    struct sockaddr_in  fromaddress;
    socklen_t           fromlen;
    doomdata_t          sw;

    fromlen = sizeof(fromaddress);
    c = recvfrom (insocket, &sw, sizeof(sw), 0
                  , (struct sockaddr *)&fromaddress, &fromlen );
    if (c == -1 )
    {
        if (errno != EWOULDBLOCK)
            I_Error ("GetPacket: %s",strerror(errno));
        doomcom->remotenode = -1;               // no packet
        return;
    }

    {
        static int first=1;
        if (first)
            printf("len=%d:p=[0x%x 0x%x] \n", c, *(int*)&sw, *((int*)&sw+1));
        first = 0;
    }

    // find remote node number
    for (i=0 ; i<doomcom->numnodes ; i++)
        if ( fromaddress.sin_addr.s_addr == sendaddress[i].sin_addr.s_addr )
            break;

    if (i == doomcom->numnodes)
    {
        // packet is not from one of the players (new game broadcast)
        doomcom->remotenode = -1;               // no packet
        return;
    }

    doomcom->remotenode = i;                    // good packet from a game player
    doomcom->datalength = c;

    // byte swap
    netbuffer->checksum = ntohl(sw.checksum);
    netbuffer->player = sw.player;
    netbuffer->retransmitfrom = sw.retransmitfrom;
    netbuffer->starttic = sw.starttic;
    netbuffer->numtics = sw.numtics;

    for (c=0 ; c< netbuffer->numtics ; c++)
    {
        netbuffer->cmds[c].forwardmove = sw.cmds[c].forwardmove;
        netbuffer->cmds[c].sidemove = sw.cmds[c].sidemove;
        netbuffer->cmds[c].angleturn = ntohs(sw.cmds[c].angleturn);
        netbuffer->cmds[c].consistancy = ntohs(sw.cmds[c].consistancy);
        netbuffer->cmds[c].chatchar = sw.cmds[c].chatchar;
        netbuffer->cmds[c].buttons = sw.cmds[c].buttons;
    }
}

int GetLocalAddress (void)
{
    char                hostname[1024];
    struct hostent*     hostentry;      // host information entry
    int                 v;

    // get local address
    v = gethostname (hostname, sizeof(hostname));
    if (v == -1)
        I_Error ("GetLocalAddress : gethostname: errno %d",errno);

    hostentry = gethostbyname (hostname);
    if (!hostentry)
        I_Error ("GetLocalAddress : gethostbyname: couldn't get local host");

    return *(int *)hostentry->h_addr_list[0];
}

//
// I_InitNetwork
//
void I_InitNetwork (void)
{
    boolean             trueval = true;
    int                 i;
    int                 p;
    struct hostent*     hostentry;      // host information entry

    doomcom = malloc (sizeof (*doomcom) );
    memset (doomcom, 0, sizeof(*doomcom) );

    // set up for network
    i = M_CheckParm ("-dup");
    if (i && i< myargc-1)
    {
        doomcom->ticdup = myargv[i+1][0]-'0';
        if (doomcom->ticdup < 1)
            doomcom->ticdup = 1;
        if (doomcom->ticdup > 9)
            doomcom->ticdup = 9;
    }
    else
        doomcom-> ticdup = 1;

    if (M_CheckParm ("-extratic"))
        doomcom-> extratics = 1;
    else
        doomcom-> extratics = 0;

    p = M_CheckParm ("-port");
    if (p && p<myargc-1)
    {
        DOOMPORT = atoi (myargv[p+1]);
        printf ("using alternate port %i\n",DOOMPORT);
    }

    // parse network game options,
    //  -net <consoleplayer> <host> <host> ...
    i = M_CheckParm ("-net");
    if (!i)
    {
        // single player game
        netgame = false;
        doomcom->id = DOOMCOM_ID;
        doomcom->numplayers = doomcom->numnodes = 1;
        doomcom->deathmatch = false;
        doomcom->consoleplayer = 0;
        return;
    }

    netsend = PacketSend;
    netget = PacketGet;
    netgame = true;

    // parse player number and host list
    doomcom->consoleplayer = myargv[i+1][0]-'1';

    doomcom->numnodes = 1;      // this node for sure

    i++;
    while (++i < myargc && myargv[i][0] != '-')
    {
        sendaddress[doomcom->numnodes].sin_family = AF_INET;
        sendaddress[doomcom->numnodes].sin_port = htons(DOOMPORT);
        if (myargv[i][0] == '.')
        {
            sendaddress[doomcom->numnodes].sin_addr.s_addr
                = inet_addr (myargv[i]+1);
        }
        else
        {
            hostentry = gethostbyname (myargv[i]);
            if (!hostentry)
                I_Error ("gethostbyname: couldn't find %s", myargv[i]);
            sendaddress[doomcom->numnodes].sin_addr.s_addr
                = *(int *)hostentry->h_addr_list[0];
        }
        doomcom->numnodes++;
    }

    doomcom->id = DOOMCOM_ID;
    doomcom->numplayers = doomcom->numnodes;

    // build message to receive
    insocket = UDPsocket ();
    BindToLocalPort (insocket,htons(DOOMPORT));
    ioctl (insocket, FIONBIO, &trueval);

    sendsocket = UDPsocket ();
}

void I_NetCmd (void)
{
    if (doomcom->command == CMD_SEND)
    {
        netsend ();
    }
    else if (doomcom->command == CMD_GET)
    {
        netget ();
    }
    else
        I_Error ("Bad net cmd: %i\n",doomcom->command);
}

